In a GPRS terminal system, the efficiency of a system and the smoothness of data transmission may be improved by reducing message sending among modules, reducing system calling, and by reasonable memory operation and management. A method for operating and managing memory is provided in the prior art. In the whole of GPRS terminal system, a transmission plane protocol layer mainly comprises a Sub-Network Dependent Convergence Protocol (SNDCP), a Logic Link Control (LLC) and a Radio Link Control (RLC). Wherein, the SNDCP provides a data access function for different types of protocols, and executes operations such as compressing data and control section, data partitioning and data assembling; the LLC provides a stable logic link between a Mobile Station (MS) and a Servicing GPRS Support Node (SGSN), and ensures a reliable transmission of data by a confirmation mechanism, an encryption mechanism; the RLC processes the LLC data packets, and then transmits the packets by a radio interface, and adopts an Auto Repeat Request (ARQ) mechanism for a transmission confirmation.
Only the Message primitives between SNDCP, LLC and RLC are specified in the 3GPP TSS (Third Generation Partnership Project Technical Specification) 44.065, 3GPP TS 44.064 and 3GPP TS44.060, however, a method for operating and managing memory during a process of data transmission is not specified.
An existing most direct method for operating and managing memory comprises, after receiving data sent by an application layer (i.e. uplink data), SNDCP compressing and partitioning the data, and assembling the partitioned data into SNDCP data packets, and storing the SNDCP data packets into the applied memory, and sending the SNDCP data packets to the LLC by the message primitive; the LLC, after receiving the SNDCP data packets, assembling the SNDCP data packets into the LLC data packets, and storing the LLC data packets into the applied memory, and sending it to the RLC by the message primitive; the RLC, after finding the to-be-sent data, starting to apply radio resource, and then sending the data.
The advantage of such method for operating and managing memory is a clear organization, there is no interference among SNDCP, LLC and RLC, data are assembled layer by layer; the method, however, has the following disadvantages:
the first, much memory space is needed, for example in the application layer, at least 3000 bytes of memory is needed to transmit 10000 bytes of data during a process of transmission, if the amount of data increases, the memory size times 3 is actually used;
the second, the application for transmission plane data area memory, the application for control plane data area memory, and the application for message memory when sending message, are all applied to one single memory, therefore, if the amount of data is too large, then the memory for data of the control plane or data for sending the message would not likely to be applied successfully, thus causing that some controls can not be performed normally;
the third, a great deal of data will be accumulated in the RLC, thus increasing the computation amount of the RLC, and thereby decreasing a transmission efficiency of the data;
the fourth, in the LLC, most of data needs to be encrypted, which generally uses a lot of resource, a failure of data transmission will cause the rebuilding of a link of LLC, all the LLC data packets sent to the RLC will be removed, such that the work completed before by the LLC becomes useless.
Moreover, a manner of memory pool also is adopted in the prior art for operating and managing the memory, which can although avoid some disadvantages of above method, but can not avoid a large number of operations such as dynamic memory application releasing and tedious memory pool operations.